1. Field
Embodiments of the present disclosure generally relate to the field of computer networks. In particular, various embodiments relate to methods and systems for configuring, arranging, placing or otherwise locating radio access points in a manner that allows optimum utilization of available radio channels and have lower channel interference for a given coverage area.
2. Description of the Related Art
Wireless communication systems are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. With the number of wireless-enabled computing devices such as smartphones, laptops, PCs, tablets, among other like devices growing by leaps, demand for wireless communication technology has grown tremendously in the last few years. Users have now come to expect long-range wireless network connections for such devices wherever they go (e.g., work, hotels, coffee shops, libraries, etc.). Typically, for each computing device to participate in a wireless communication, the device needs to have an in-built radio transceiver or has to be operatively coupled to a radio transceiver.
A wireless Access Point (AP) is an example of a wireless network device that comprises one or more radios and allows computing devices to connect to a wired network or other computing devices. A wireless AP typically includes a local link interface to communicate with local client devices, and a downlink/uplink interface to communicate with other APs. With the creation of APs, network users and/or administrators are able to add computing devices to a network with few or no cables and are able to increase available bandwidth to wireless-enabled computing devices by deploying additional APs tuned to non-overlapping channels. An AP may be directly connected to a wired Ethernet connection, providing wireless connections to other devices to utilize the wired connection of Ethernet using radio frequency links. APs may support connection of multiple computing devices to a single wired connection and may send/receive data packets using radio frequencies defined by the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of wireless networking standards.
Typically, a radio, depending on its characteristics, has multiple channels and a defined coverage range. For instance, a 2.4 GHz frequency radio has 3 non-overlapping channels (1, 6, and 11) and a 5 GHz frequency radio has 37 channels (where the number of actual usable channels depends on, among other factors, the make of the AP, indoor or outdoor placement of the AP, height above ground, nearby obstructions, type of antenna, etc.). The range of a typical 5 GHz radio AP is half of that of a typical 2.4 GHz radio AP. As multiple radios may be incorporated in a single AP, it is important to have non-overlapping channels within the AP and across multiple APs. For instance, in a dual band/radio AP, one channel of 2.4 GHz may be positioned along with one channel of 5 GHz radio, allowing concurrent 2.4 GHz and 5 GHz access across 802.11a/n and 802.11b/g/n connections. Configuration of multiple dual APs in a building or an infrastructure, each having a 2.4 GHz and a 5 GHz radio, may involve repeating of one or more channels for 2.4 GHz radio APs for every fourth AP, which makes the infrastructure non-efficient as 2.4 GHz radio APs have longer range and therefore closely placed 2.4 GHz radio APs are bound to have co-channel interference. As such, high-density configurations of 2.4 GHz radio APs contributes to underutilization of potential bandwidth that may be provided by the 2.4 GHz radio APs. In continuation, in existing solutions that have both 2.4 GHz and 5 GHz radios in a dual AP, in a building that requires a large number of APs to be configured, say twenty non-overlapping 5 GHz channels, 20 different APs, each having a 5 GHz radio would be needed, which further makes the wireless network architecture expensive and substantially more cumbersome.
Furthermore, RF signals, when transmitted, do not just stop at the clients for which they are intended. Therefore, the RF energy in the RF signals, when strong enough, may to cause clients to defer transmissions due to “busy” clear channel assessments. The distance traveled by RF signals might be hundreds of feet indoors, depending on the environment. In addition to the energy emitted by AP transmissions, energy emitted by client transmissions also needs to be considered and taken into account, which the existing solutions fail to do. As clients move away from APs while transmitting, they cause co-channel interference at an even greater range than the AP may cause, for which reason, it is important to avoid interference from such clients.
FIGS. 1A and 1B illustrate an exemplary co-channel interference issue in the context of a typical dual radio access point (AP) configuration 100. As can be seen, FIG. 1 illustrates multiple 2.4 GHz/5 GHz APs 102-1, 102-2, 102-3, . . . , 102-20, collectively referred to as 102 hereinafter, wherein 3 channels (1, 6, and 11) of 2.4 GHz, and 20 channels (36, 40, . . . , 149) of 5 GHz are configured in the network architecture. In addition, four additional channels (153, 157, 161, and 165) of 5 GHz have been shown as being unutilized. In such an architecture, as channels 1, 6, and 11 of 2.4 GHz are configured closely with each other (yielding higher density configuration), as shown in FIG. 1B, and have a longer range when compared with those of channels of 5 GHz radio, co-channel interference increases significantly and a number of 2.4 GHz radios would go underutilized in case such interference is attempted to be handled by disabling channels of certain 2.4 GHz radios. As shown through representation 150 of FIG. 1B, channel 6 of the 2.4 GHz radios is densely packed giving high interference. Yet another disadvantage of this configuration 100 relates to antenna coupling, which is caused when two antennas (configured to radiate and/or receive radio signals) exist in the same frequency band and are close to each other so as to cause energy from one antenna to couple with that of the other and appear as the received signal. Such received signals result in loss of gain and directional transmission overlap, which is undesirable.
There is therefore a need for an efficient AP and configuration thereof that can help optimally use available channels, prevent co-channel interference, and further reduce/prevent antenna coupling and issues related thereto. This problem addressed by this disclosure is applied mainly for in indoor AP installations.